The invention relates to an electromagnet, comprising a coil which can be supplied with current and which thus generates a magnetic field and moves an armature when supplied with current, and wherein the armature serves for controlling a valve or another element, the movement of the armature being damped by one or more damping elements.
Aforementioned electromagnets are widely used in the field of engineering. They serve, for example in textile machines, for a rapid weft insertion.
The above-described electromagnets also serve, however, for the control of gaseous and liquid media (in particular in liquid or hydraulic circuits), for example in a valve or as a control electromagnet or solenoid in applications where service life and time are critical.
Use in weaving machines or other textile machines, particularly, demands a high performance of electromagnets. The electromagnets are expected to achieve extremely high service-life requirements and switching frequencies. This results in considerable mechanical stresses on the electromagnet and the movably mounted elements.
German patent 31 32 396 describes an electromagnet which uses resilient elements as damping bodies which absorb the kinetic energy of the armature and thus avoid premature wear of the electromagnet.
In order to achieve the high clock frequencies, corresponding accelerations of the armature must be achieved. Particular importance is attached in this regard to the bearing of the armature, since an inaccurate bearing of the armature can lead to unequal stress on the damping elements, which then wear preferentially at these locations, and then jeopardizes the entire usability of the device.
Owing to the high frequencies, there is also considerable development of heat in the magnet coil. This leads, for reasons of design, to larger air gaps in order to allow constructionally for the thermal expansion of the components. However, on the other hand, this limits the effective magnet gaps and thus reduces the efficiency of the device.